How do I "hide" controls that my control uses from the toolbox?

I have developed a control in C#. Among other things this control can popup other controls at runtime. When you include the assembly in Visual Studio, the control that I created shows up, but the other controls (the ones my control uses) show up as well. I would rather not have them show up in the toolbox in Visual Studio. Is there an Attribute that I can apply to these classes to make them not show up? I found the browsable attribute, but it says it is for properties and events.